body {
    font-family: "Segoe UI", Arial, "Microsoft Yahei", sans-serif;
    font-size: 90%;
    display: flex;
    width: 780px;
    height: 580px;
    margin: 0;
}

* {
    box-sizing: border-box;
}

.container {
    display: flex;
    flex-direction: column;
    width: 100%;
    height: 100%;
}

.panel_top {
    margin: 5px;
    padding: 5px;
    height: 5%;
}

.panel_main {
    display: flex;
    flex-direction: row;
    /*margin: 5px;*/
    /*padding: 5px;*/
    height: 95%;
}

.sidebar {
    display: flex;
    flex-direction: column;
    width: 40%;
    height: 100%;
    /*margin: 5px;*/
    /*padding: 10px;*/
}

ul {
    list-style-type: none;
    margin-left: -20px;
}

li {
    list-style-type: none;
    padding-left: 20px;
    margin: 5px;
}

.file-list li {
    margin-left: 5px;
    margin-top: 10px;
    margin-bottom: 10px;
    color: #2b2f2f;
    background: #e6efe6;
    border: thin solid #b8cbb8;
    border-width: 2px;
}

.expand {
    -webkit-transform: rotate(-90deg);
    background-image: url();
    opacity: 1;
    /*top: 6px;*/
    display: inline-block;
    width: 16px;
    height: 16px;
    vertical-align: top;
    position: relative;
    background-size: 16px;
}

.sh-broder {
    background-color: #cdead9;
    /*padding: 10px;*/
    /*margin: 5px;*/
    border: thin solid #8d9956;
    border-width: 2px;
}

.tree-item {

}

.tree-row {
    user-select: none;
}

.tree-children {
    margin-left: 20px;
}

.folder {
    background-image: url();
    background-repeat: no-repeat;
    background-size: 16px;
    padding-left: 20px;
    width: 100%;
}

.folder-tree {
    height: 30%;
    margin: 5px;
    overflow-x: auto;
    overflow-y: scroll;
}

.file-list {
    height: 70%;
    margin: 5px;
    overflow-x: auto;
    overflow-y: scroll;
}

.tabs {
    display: flex;
    width: 100%;
    height: 3.5%;
}

.tab-button {
    display: flex;
    justify-content: center;
    align-items: center;
    flex: 1;
    padding: 10px 20px;
    background-color: #f1f1f1;
    border: 1px solid #ccc;
    cursor: pointer;
    transition: background-color 0.3s;
}

.tab-button:hover {
    background-color: #ddd;
}

.tab-content {
    border: 1px solid #ccc;
    /*padding: 20px;*/
    background-color: #fafafa;
    display: flex;
    flex-direction: column;
    /*justify-content: center;*/
    align-items: center;
    width: 100%;
    height: 96.5%;
    overflow: auto;
}

.preview {
    width: 60%;
    margin: 5px;
    /*padding: 10px;*/
    box-sizing: border-box;
    /*overflow: auto;*/
}

.preview-img-div {
    display: grid;
    /*grid-column-gap: .3rem;*/
    /*-moz-column-gap: .3rem;*/
    column-gap: .3rem;
    /*grid-row-gap: 1rem;*/
    row-gap: .3rem;
    grid-template-columns: repeat(1,auto);
    margin: 5px;
}

/*.preview-img-div {*/
/*    isplay: flex;*/
/*    flex-wrap: wrap;*/
/*    !*justify-content: center;*!*/
/*    margin: 5px;*/
/*    align-items: center;*/
/*}*/

.preview-img {
    max-width: 1080px;
    width: 100%;
    /*max-height: 100%;*/
    /*margin: 2px;*/
}

.prelong-img {
    /*max-width: 1080px;*/
    width: 100%;
    /*max-height: 100%;*/
    /*margin: 2px;*/
}